An indepth look at weather and climate by South Carolina's Weatherman Jim Gandy.

Friday, September 14, 2012

The Heat Is On

Image Credit: Climate Central.

The January-August period was the
warmest first eight months of any year on record for the contiguous United
States. The national temperature of 58.7°F was 4.0°F above the 20th century
average, and 1.0°F above the previous record warm January-August of 2006.
During the eight-month period, 33 states were record warm and an additional 12
states were top ten warm. Only Washington had statewide temperatures near
average for the period.

The statewide ranks of temperatures since 1895 and the top ten warmest January-August periods in South Carolina. Image Credit: NOAA\NCDC.

Climate Central has developed an
interactive map that illustrates the record heat experienced across the
country.Not only has it been the hottest year in the U.S. since recordkeeping began in 1895,
but so far more than 28,000 individual daily high-temperature records have been
matched or broken.

The “Number of Records” map simply shows how many
records were set in each state.

Since some states have a lot more measuring stations
than others, the “Records/Station” map shows how many daily records were
broken, on average, at each station, in order to give equal weight to
states with fewer stations.

The “vs. Expected” map takes into account how difficult
it actually is to break a record, based on what year data collection began
(for example, a station that’s been recording for 100 years will have had
more chances to set a very high record, which is harder to break, than a
station that’s only 40 years old).

The “Ratio to Low” map ranks states on how much
high-temperature records outnumber low-temperature records.

Finally, the “Overall” map represents an average of all
these measures, in order to show which states broke the most records and
how unusual these records are.

The “Ratio to Low” map provides a
useful way of showing that record high temperatures have outnumbered record low
temperatures all over the country. In an unchanging climate, the ratio of
record highs to record lows is expected to be roughly 1:1 on average and in the
long term. A ratio greater than 1:1 suggests a warming climate. This year, not
a single state has seen more lows than highs, or even a 1:1 ratio. This follows
a string of years in the last decade or so during which the record high to
record low ratio over the U.S. has been persistently and significantly larger
than 1 as a long term trend.

This is what you find for South
Carolina:

Image Credit: Climate Central.

South
Carolina comes in39th in the overall
ranking. However, it has a large ratio of record highs to record lows (almost
5:1). While this is below the national average of 13.37, it still means that
every time a station reported a record low temperature, 5 other stations
reported record highs.

The average summer temperature
turned out to be near normal for Columbia in spite of setting an all-time
record high of 109 F on the last two days of June.It was 106 F on July 1, but the humidity was
much higher and the heat index reached 119 F followed by severe
thunderstorms.It still turned out to be
the hottest January-August period since the National Weather Service Forecast
Office was relocated to the airport in 1948.

Image Credit: Climate Central.

The past five month have seen the
top five warmest 12-month periods for the country since records began in 1895.

The warmest 12-month periods. Image Credit: NOAA\NCDC.

Clearly 2012 is on track to be the
warmest year on record.Keep in mind
that this is only for the contiguous United States and is not for the
globe.That remains to be played out,
but I discussed this back in January in this post.

About Me

A professional meteorologist for over 37 years, Jim Gandy is the chief meteorologist at WLTX-TV (CBS affiliate) in Columbia, SC. He has held that position since 1999.
Jim is a Certified Broadcast Meteorologist and has a number of awards and recognitions for his work over the years. He is best known for his forecast of Hurricane Hugo in 1989 and his work during the tornado outbreak in South Carolina in 1994.
Jim continues to study weather and is interested in climate change which he has studied since 2005. Looking for better ways to communicate climate change, he is working with the Center for Climate Change Communication at George Mason University and with Climate Central.
Jim recently began working with the Helmuth Lab at the University of South Carolina. Dr. Brian Helmuth is working in the area of the effects of climate change on the ecology.
All of these subjects are of vital interest to South Carolina.